Improvement in sheet-fvjetal screw-rings



L. F. BETTS.`

Improvement in Sheet Metal Screw Rings.

' N0; 124,320*I PatentedMarch 5,1872.

AM. PHara-Ur/mchAPH/e ca. Mylossomlslr Palm-:

UNITEgn STATES LnwIs F. nnrrs, or' PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN SHTlVlTAL SCREW-RINGS.

Specification forming part of Letters Patent No. 124,320, dated March 5, 1872.

Specification describing an Improvement in Sheet-Metal Screw-Rings and mode of making the same, invented by LEWIS F. BET'IS, of Philadelphia, Pennsylvania.

Improvement in Sheet-Metal Screw-Rings and Mode of Making the Same.

My invention relates to the manufacture of the sheet-metal screw-rings now commonly used for confining the covers of fruit-j ars, such rings having iianges for bearing on the covers and pressed screw-threads adapted to a similar thread on the jar; and my improvement consists of a screw-ring made in the peculiar manner fully described hereafter with a view to economy in the consumption of material.

Figure l is a side view of the strip of sheet metal as it appears before it is bent; Fig. 2, a sectional view of Fig. 1 on the line l 2; Fig. 3 a sectional plan of the strip as it appears when bent to the form of a ring and united at the opposite ends; Fig. 4, a perspective View of the ring; Fig. 5, the ring as it appears when threaded; and Figs. 6 and 7, diagrams illustrating modifications of my invention.

In makin g the well-known sheet-metal screwrings for fruit-jars it has been the practice to first punch out from sheets of metal disks which are subsequently formed into a cup-shape by the action of dies; then threaded in a machine; and final] y each threaded cup has a disk punched from it so as to complete the screwring. Although effective and perfect rings were made by this process, it involved the waste of a large amount of material, -owin g to the disk, which had to be cut from each threaded cup and thrown aside.

In order to avoid this waste I make the sheetmetal rings in the following manner: I first cut from the sheet of metal a series of strips, A, (Figs. l and 2,) each strip being of sufficient length and width to form a ring of the desired diameter and depth. Throughgthe strip, near one end of the same, I punch two plain holes, a a, and near the opposite end of the strip I punch two holes, b b, with such a punch and die that an annular rib or burr, e, will project on one side of the strip, aroundthe edge of each hole. of a ring, Fig. 3, taking care that the ends so overlap that the annular ribs e e at one end of I now bend the strip into the form the strip shall enter the holes a a at the opposite end; ra slight pressure imparted to these annular ribs by an eyelet-machine or other suitable instrument will then -rivet the two ends of the strip together sufficiently tight to enable the rings to withstand the remaining branches of the process, which consist, first, informing the ange x, Fig. 5, and then forming a screwthread on the body of the rings. The formation of the flange by turning in the upper edge of the ring may be accomplished by any of the many machines used by sheet-metal workers for like purposes.

The threading of the ring may be effected in the machine for which Letters Patent were granted to S. B. Rowley, assignee of Thos. Houghton, September 2, 1869, in which the thread is formed by causing a roller to force the metal into the internal thread of a revolving screw-chuck. This operation of threading the ring effectually completes the union of the opposite ends of the strips, owing to the pressure exerted on the annular rivet or eyelet c, through which the junction is accomplished.

Attempts have been made to form screwrings from strips of metal, the overlapping ends being soldered, but independently of the expense of making a soldered joint, the solder interferes with the proper formation of the screw. I have found, moreover, that solid rivets at the junction ofthe opposite ends of the strip are not only expensive but interfere with the proper formation of the screw, as in the case of the soldered joint; the eyelet-like rivets, on the contrary, yield and accommodate themselves to the pressure applied to the metal in making the screw-thread, while it has been found that the eyelet-holes facilitate the easy threading of the ring, because the superliuous metal iiows into the opening instead of forming ridges on the ring.

Plain holes a a may be'punched through the strip at both ends ofthe same and the fastenings .made with ordinary'eyelets y, as shown by the diagram, Fig. 6; or, instead of being punched through, the strip may be merely indented on one side, so as to form a corresponding projection at the opposite side, as shown in Fig. 7, the said projection being passed through a plain hole punched in the opposite end ofthe strip and then flattened in the same manner as an eyelet to complete the fastening. The factthatthe end ofthe projection is opened when it is spread, or even when it is formed, does not aect the security 0f the fastening, which results from the projection being so eX panded as to rivet the two ends of the strip together. I prefer, however, to form an annular rivet or eyelet on the strip, as shown in Figs. 1 and 2 and described above.

It will be unnecessary to explain how economy in the consumption of material is attained by manufacturing screw-rings in accordance with my invention.

e. In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

LEWIS F. BETTS.

Witnesses:

WM. A. STEEL, HARRY SMITH. 

